50. Bonnie Raitt

"For many years, I couldn't stand listening to my own voice," says Bonnie Raitt. "Not enough gravitas or experience to convey the depth of emotion I wanted to express." But Raitt would become a blues force all her own on songs such as the ferocious "Love Me Like a Man" from 1972, combining influences ranging from Ray Charles and Joan Baez to Muddy Waters, as well as her father, John Raitt, a star of Broadway musicals. By the time of 1989's Nick of Time and 1991's Luck of the Draw, she had grown into her vocal ambitions, most obviously in her heart-rending delivery of ballads such as "I Can't Make You Love Me." "I've never been one to think about how to sing," says Raitt. "Once I start, I'm just living it. I prefer to just let 'er rip."